In a construction worksite, a plurality of work machines and workers are arranged in accordance with the contents of construction, and the work machines and the workers perform work while moving therein. In order to improve the safety and perform smooth construction management at the worksite, it is important to constantly monitor and grasp the positions of the work machines and the workers.
Accordingly, in Patent Literature 1, it is disclosed “each GPS positioning device is attached to such as a heavy machine and a worker in a monitoring area, and a transmitter transmits an individual mobile object position signal, which includes positions received from the positioning devices and identification signals of the mobile objects, to a management room. A receiver in the management room receives the individual mobile object position signal, and an allocation means allocates predetermined approach detection areas around the positions of the received mobile objects. An intersection detection means detects an intersection between the approach detection areas of the mobile objects, and outputs an intersection detection signal and the mobile objects related to the intersection at the time of the intersection detection. A notification device provided in the management room transmits an intersection notification signal, which includes the intersection detection signal and identification signals of the mobile objects relating to the intersection, and intersection receiving devices attached to each mobile object detects the intersection notification signal including the identification signal of each mobile object (extracted from Abstract)”.
Furthermore, in Patent Literature 2, it is disclosed “a surrounding monitoring device for a work machine, comprises: a work machine posture capturing means for capturing the posture and the shape of the work machine at the time of performing work; a camera for taking images of the surrounding of the work machine; an obstacle detecting means for measuring the obstacle around the work machine and its position; a display image generating means for composing an image in which the posture, the shape, and a work range of the work machine are drawn based on information from the work machine posture capturing means, an image of the surrounding of the work machine which is taken by the camera, and an image in which the obstacle detected by the obstacle detecting means is drawn so as to generate a display image; and a display means for displaying the generated image (extracted from Abstract).
Still further, in Patent Literature 3, it is disclosed “a work machine (hydraulic excavator) comprises a camera; a GPS receiver; a wireless transceiver for receiving positional information measured by a GPS receiver provided in another work machine and a GPS receiver carried by a worker; an warning sound generating device for notifying a driver that another work machine or another worker has entered a monitoring range; a display device for displaying a camera image; and a monitoring controller. A safety management device is configured by the work machine configured as above, an intrusion information management computer provided outside the work machine such as in a management office, an information terminal for transferring intrusion information collected by the work machine to the intrusion information management computer, a GPS receiver carried by the worker, and a wireless transceiver (extracted from Abstract)”.